Building geo-search for India means indexing 30,000+ pincodes, 742 districts and 28 states with sub-200ms lookup. PostGIS makes it doable — but the defaults will not get you there.
GiST vs SP-GiST
We benchmarked both. For our workload — nearest-neighbour with 2-3 secondary filters — GiST won by ~18%.
The KNN gotcha
The <-> operator is the magic that makes "nearest 10 cold storages to me" a single query. But you need a covering index that includes the geom column, or it falls back to a full scan.
